Employee refusing to wear PPE i work in a similar industry, and we simply can't have non compliance with cut gloves.
This should be made clear at induction, if there is an issue with the PPE issued then try other types until you find the right glove.... if they can't wear or use the PPE, after you have done everything possible to find suitable gear then take them off the knives and eliminate the risk.
Staff should not be doing the job if they can not or will not abide by the PPE requirements.
Supervision needs to be looked at, some things need to be handled in a firm manner.